Vector

#include<bits/stdc++.h>

using namespace std;
int main(){

    vector<int> v;

    v.push_back(34);
    v.push_back(45);
    v.push_back(21);

    int s = v.size(); //3

    for(int i=0; i<s; i++){
        cout<<v[i]<<endl;
    }

    //A vector of size 5, and all values are 1

    vector<int> arr(5,1);

    for(int i = 0; i<arr.size(); i++){
        cout<<"arr value = "<<arr[i]<<endl;
    }

    vector<vector<int>> a(3, vector<int>(4,0));

    int sizeOfColumn = v[0].size();

}